When Sally Marie was told she had to strip off in the name of contemporary dance, she was happy to oblige – in theory, anyway. The British dancer had been cast in Dear Body, a 2009 work by Luca Silvestrini that satirised the hard dieting, gym-bound madness of body beautiful obsessives. Marie approved of the work's politics, which she felt applied to her own profession, too. "I'd been arguing for ages that we needed a greater variety of bodies and ages in dance," says Marie, who readily admits to being a stone heavier and a decade older than most of the other dancers. "It felt like an important statement to be on stage showing my tits."

But in practice, when it came to getting naked, Marie was petrified. "When you're in a sauna, it feels completely natural. But on stage, you're really exposed." Ironically, by the time she came to perform Dear Body, she was much slimmer. "I'd been too frightened to eat."

Javier de Frutos, the Venezuelan-born choreo-grapher, understands her terror. In the 1990s, his own compact buttocks and bobbing penis became a familiar sight to audiences, in works such as the solo Gypsy and the trio Grass. Yet at first, De Frutos found crossing over into nudity traumatic. "When I was young, I was the guy at the gym who had to wait until the changing room was empty before I could take off my clothes." His mentor, the US dancer and choreo-grapher Sara Rudnor, persuaded him to change. "Sarah told me I needed to explore as many emotions as possible on stage. She told me to do what I feared most. For me, that was being naked."

De Frutos and Marie may feel some sympathy with the cast of Un Peu de Tendresse Bordel de Merde!, which arrives in Britain this week. A Little Tenderness for Crying Out Loud!, in its English translation, was created by Canadian choreographer Dave St-Pierre. It's a work exploring the fears and fantasies of 22 characters as they search for love in a brutal world. But it's also a work in which the dancers have to perform naked for much of the time; in fact, even more exposingly, they have to bring their nakedness right down into the auditorium, clambering over the stalls and fighting in the aisles – with their breasts, genitals and buttocks in wobblingly close proximity to the audience.

What's the justification for such aggressive nudity? St-Pierre, who is fascinated by taboos and the breaking of them, is trying to create a raw physical intimacy between dancer and audience, and he wants to make us laugh, too. Michael Watts, one of his dancers, says most people find the naked scenes funny. But, he adds, "we're being very childlike – we're behaving like six-year-old boys, and we get a lot of taps on the bottom from old ladies". They do occasionally encounter angry resistance, though. "One woman just hid her face completely," recalls Watts. "She put her jacket over her face. Another man got up and tried to run away. And a few dancers have got hit or pushed."

Choreographers may have many serious motives for nudity – be they political, aesthetic or psychological – but what some people find beautiful and expressive, others will inevitably find titillating or arousing, and others embarrassing or disgusting. What is certain, though, is that the issue of how much flesh a dancer shows has always been controversial. In 1725, when ballerina Marie Camargo shortened her skirts to ankle length to gain extra freedom of movement, there were many who went to the Paris Opera not to applaud her virtuosity but to catch a flash of calf or thigh. Camargo was credited with inventing an early form of knickers to preserve some modesty as she danced.

For Isadora Duncan, the American who began performing her radiant, radical dance recitals around 1900, the body was sacred. When she abandoned corsets, danced barefoot and occasionally let a bare breast spill out of her loosely draped tunic, Duncan wasn't simply serving the cause of dance, she was celebrating the human spirit. And her inspiration, as well as her notoriety, led to more dancers stripping off in the name of high art. Canadian Maud Allan became a superstar of Edwardian Britain thanks her near-naked Salomé routine, and Josephine Baker was dubbed the Ebony Venus when she danced in Paris wearing nothing but a belt of pink feathers or a tiny skirt of fake bananas.

When stage censorship laws were relaxed during the 1960s, however, even a coy veil could be dispensed with. The cast of musicals such as Oh! Calcutta! paraded their bodies with joy, while avant-garde choreographers began to explore the gamut of what nudity could signify. Yvonne Rainer, in 1970s New York, danced naked in front of a US flag to protest against the Vietnam war. And veteran British dancer Diana Payne-Myers developed an entire second career when choreo-graphers such as Lloyd Newson started to explore the potential of putting a much older, naked dancer on stage.

Since the late 1990s, Payne-Myers's tiny, wrinkled, supple form has evoked images of survival, defenselessness and even the joy of supposedly inappropriate elderly behaviour.

For De Frutos, as he explored the feelings of vulnerability created by dancing naked, other issues arose. He became fascinated by his audiences' natural voyeurism and by the ways he could deflect it. "I wanted to take their attention away from my genitalia to all the small muscles in the body, and show how eloquent they are. There is something irreplaceable about the sensual reality of skin, and the beauty of light falling on skin. I was always thinking how that could best be achieved."

Visually, De Frutos was inspired by none other than Caravaggio and El Greco. But in real life, the human body can be an unruly beast: it gets rashes and bruises, it's subject to weight gain, hairiness and menstrual cycles – as well as other kinds of normally private activity. De Frutos swears he never worried about getting an erection on stage when performing with other nude dancers: "Dancing naked," he says, "is the least sexy thing I've ever done." And Sally Marie was convinced that all the men in Dear Body were "very anxious. During contact, everyone was trying to keep a distance between their pelvises. It was very funny. "

For Arthur Pita, the London-based choreographer of the pastoral comedy Camp, the issue was simply his own vanity. He hadn't expected to dance in Camp, but when he had to take over from an injured cast member he went straight into an intensive regime of "squats and press-ups" to prepare for his naked scene. "I really didn't want anything to be wobbling for the audience."

Pita envies the lack of self conscious-ness shown by Payne-Meyers, with whom he has worked. "She knows full well she is an 83-year-old woman, but she is completely committed to her art and completely unembarrassed. Her body is amazing to look at. It's only skin and bone and muscle, but it's very old skin and bone and muscle. I admire that healthy, honest approach; it's something all dancers should be inspired by."

Tendresse comes with a guidance rating of 18, and all its publicity contains warnings of "explicit adult material". What's more, Michael Watts is keen to point out that if anyone in the audience obviously hates what the dancers are doing, they won't get picked on. "We can usually tell how people are feeling," he says. "They won't actually have a hairy man in a wig clambering over them."